<template>
  <view class="container">
    <!-- 空白页 -->
    <view
      v-if="!hasLogin || empty===true"
      class="empty"
    >
      <image
        src="/static/emptyCart.jpg"
        mode="aspectFit"
      />
      <view
        v-if="hasLogin"
        class="empty-tips"
      >
        空空如也
        <navigator
          v-if="hasLogin"
          class="navigator"
          url="../index/index"
          open-type="switchTab"
        >
          随便逛逛>
        </navigator>
      </view>
      <view
        v-else
        class="empty-tips"
      >
        空空如也
        <view
          class="navigator"
          @click="navToLogin"
        >
          去登陆>
        </view>
      </view>
    </view>
    <view v-else>
      <!-- 列表 -->
      <view class="cart-list">
        <block
          v-for="(item, index) in cartList"
          :key="item.id"
        >
          <view
            class="cart-item" 
            :class="{'b-b': index!==cartList.length-1}"
          >
            <view class="image-wrapper">
              <image
                :src="item.image" 
                :class="[item.loaded]"
                mode="aspectFill" 
                lazy-load 
                @load="onImageLoad('cartList', index)" 
                @error="onImageError('cartList', index)"
              />
              <view 
                class="yticon icon-xuanzhong2 checkbox"
                :class="{checked: item.checked}"
                @click="check('item', index)"
              />
            </view>
            <view class="item-right">
              <text class="clamp title">
                {{ item.title }}
              </text>
              <text class="attr">
                {{ item.attr_val }}
              </text>
              <text class="price">
                ¥{{ item.price }}
              </text>
              <uni-number-box 
                class="step"
                :min="1" 
                :max="item.stock"
                :value="item.number>item.stock?item.stock:item.number"
                :is-max="item.number>=item.stock?true:false"
                :is-min="item.number===1"
                :index="index"
                @eventChange="numberChange"
              />
            </view>
            <text
              class="del-btn yticon icon-fork"
              @click="deleteCartItem(index)"
            />
          </view>
        </block>
      </view>
      <!-- 底部菜单栏 -->
      <view class="action-section">
        <view class="checkbox">
          <image 
            :src="allChecked?'/static/selected.png':'/static/select.png'" 
            mode="aspectFit"
            @click="check('all')"
          />
          <view
            class="clear-btn"
            :class="{show: allChecked}"
            @click="clearCart"
          >
            清空
          </view>
        </view>
        <view class="total-box">
          <text class="price">
            ¥{{ total }}
          </text>
          <text class="coupon">
            已优惠
            <text>74.35</text>
            元
          </text>
        </view>
        <button
          type="primary"
          class="no-border confirm-btn"
          @click="createOrder"
        >
          去结算
        </button>
      </view>
    </view>
  </view>
</template>

<script>
import {
  mapState
} from 'vuex'
import uniNumberBox from '@/components/uni-number-box.vue'
export default {
  components: {
    uniNumberBox
  },
  data() {
    return {
      total: 0, // 总价格
      allChecked: false, // 全选状态  true|false
      empty: false, // 空白页现实  true|false
      cartList: [],
    }
  },
  onLoad(){
    this.loadData()
  },
  watch:{
    // 显示空白页
    cartList(e){
      const empty = e.length === 0
      if(this.empty !== empty){
        this.empty = empty
      }
    }
  },
  computed:{
    ...mapState(['hasLogin'])
  },
  methods: {
    // 请求数据
    async loadData(){
      const list = await this.$api.json('cartList') 
      const cartList = list.map(item => {
        item.checked = true
        return item
      })
      this.cartList = cartList
      this.calcTotal() // 计算总价
    },
    // 监听image加载完成
    onImageLoad(key, index) {
      this.$set(this[key][index], 'loaded', 'loaded')
    },
    // 监听image加载失败
    onImageError(key, index) {
      this[key][index].image = '/static/errorImage.jpg'
    },
    navToLogin(){
      uni.navigateTo({
        url: '/pages/public/login'
      })
    },
		// 选中状态处理
    check(type, index){
      if(type === 'item'){
        this.cartList[index].checked = !this.cartList[index].checked
      }else{
        const checked = !this.allChecked
        const list = this.cartList
        list.forEach(item => {
          item.checked = checked
        })
        this.allChecked = checked
      }
      this.calcTotal(type)
    },
    // 数量
    numberChange(data){
      this.cartList[data.index].number = data.number
      this.calcTotal()
    },
    // 删除
    deleteCartItem(index){
      // const list = this.cartList
      // const row = list[index]
      // const id = row.id
      // 接口根据id删除
      this.cartList.splice(index, 1)
      this.calcTotal()
      uni.hideLoading()
    },
    // 清空
    clearCart(){
      uni.showModal({
        content: '清空购物车？',
        success: (e) => {
          if(e.confirm){
            this.cartList = []
          }
        }
      })
    },
    // 计算总价
    calcTotal(){
      const list = this.cartList
      if(list.length === 0){
        this.empty = true
        return
      }
      let total = 0
      let checked = true
      list.forEach(item => {
        if(item.checked === true){
          total += item.price * item.number
        }else if(checked === true){
          checked = false
        }
      })
      this.allChecked = checked
      this.total = Number(total.toFixed(2))
    },
    // 创建订单
    createOrder(){
      const list = this.cartList
      const goodsData = []
      list.forEach(item => {
        if(item.checked){
          goodsData.push({
            attr_val: item.attr_val,
            number: item.number
          })
        }
      })

      uni.navigateTo({
        url: `/pages/order/createOrder?data=${JSON.stringify({
          goodsData: goodsData
        })}`
      })
      this.$api.msg('跳转下一页 sendData')
    }
  }
}
</script>

<style lang='scss'>
	.container{
		padding-bottom: 134rpx;
		/* 空白页 */
		.empty{
			position:fixed;
			left: 0;
			top:0;
			width: 100%;
			height: 100vh;
			padding-bottom:100rpx;
			display:flex;
			justify-content: center;
			flex-direction: column;
			align-items:center;
			background: #fff;
			image{
				width: 240rpx;
				height: 160rpx;
				margin-bottom:30rpx;
			}
			.empty-tips{
				display:flex;
				font-size: $font-sm+2rpx;
				color: $font-color-disabled;
				.navigator{
					color: $uni-color-primary;
					margin-left: 16rpx;
				}
			}
		}
	}
	/* 购物车列表项 */
	.cart-item{
		display:flex;
		position:relative;
		padding:30rpx 40rpx;
		.image-wrapper{
			width: 230rpx;
			height: 230rpx;
			flex-shrink: 0;
			position:relative;
			image{
				border-radius:8rpx;
			}
		}
		.checkbox{
			position:absolute;
			left:-16rpx;
			top: -16rpx;
			z-index: 8;
			font-size: 44rpx;
			line-height: 1;
			padding: 4rpx;
			color: $font-color-disabled;
			background:#fff;
			border-radius: 50px;
		}
		.item-right{
			display:flex;
			flex-direction: column;
			flex: 1;
			overflow: hidden;
			position:relative;
			padding-left: 30rpx;
			.title,.price{
				font-size:$font-base + 2rpx;
				color: $font-color-dark;
				height: 40rpx;
				line-height: 40rpx;
			}
			.attr{
				font-size: $font-sm + 2rpx;
				color: $font-color-light;
				height: 50rpx;
				line-height: 50rpx;
			}
			.price{
				height: 50rpx;
				line-height:50rpx;
			}
		}
		.del-btn{
			padding:4rpx 10rpx;
			font-size:34rpx; 
			height: 50rpx;
			color: $font-color-light;
		}
	}
	/* 底部栏 */
	.action-section{
		/* #ifdef H5 */
		margin-bottom:100rpx;
		/* #endif */
		position:fixed;
		left: 30rpx;
		bottom:30rpx;
		z-index: 95;
		display: flex;
		align-items: center;
		width: 690rpx;
		height: 100rpx;
		padding: 0 30rpx;
		background: rgba(255,255,255,.9);
		box-shadow: 0 0 20rpx 0 rgba(0,0,0,.5);
		border-radius: 16rpx;
		.checkbox{
			height:52rpx;
			position:relative;
			image{
				width: 52rpx;
				height: 100%;
				position:relative;
				z-index: 5;
			}
		}
		.clear-btn{
			position:absolute;
			left: 26rpx;
			top: 0;
			z-index: 4;
			width: 0;
			height: 52rpx;
			line-height: 52rpx;
			padding-left: 38rpx;
			font-size: $font-base;
			color: #fff;
			background: $font-color-disabled;
			border-radius:0 50px 50px 0;
			opacity: 0;
			transition: .2s;
			&.show{
				opacity: 1;
				width: 120rpx;
			}
		}
		.total-box{
			flex: 1;
			display:flex;
			flex-direction: column;
			text-align:right;
			padding-right: 40rpx;
			.price{
				font-size: $font-lg;
				color: $font-color-dark;
			}
			.coupon{
				font-size: $font-sm;
				color: $font-color-light;
				text{
					color: $font-color-dark;
				}
			}
		}
		.confirm-btn{
			padding: 0 38rpx;
			margin: 0;
			border-radius: 100px;
			height: 76rpx;
			line-height: 76rpx;
			font-size: $font-base + 2rpx;
			background: $uni-color-primary;
			box-shadow: 1px 2px 5px rgba(217, 60, 93, 0.72)
		}
	}
	/* 复选框选中状态 */
	.action-section .checkbox.checked,
	.cart-item .checkbox.checked{
		color: $uni-color-primary;
	}
</style>
